Bangladesh's finance minister has downplayed the impact of the factory-building collapse on his country's garment industry, saying he didn't think it was "really serious" hours after the 500th body was pulled from the debris.

Bangladesh's finance minister has downplayed the impact of the factory-building collapse on his country's garment industry, saying he didn't think it was "really serious" hours after the 500th body was pulled from the debris.

Abul Maal Abdul Muhith spoke as the government cracked down on those it blamed for the disaster in the Dhaka suburb of Savar.

It suspended Savar's mayor and arrested an engineer who had called for the building's evacuation last week, but was also accused of helping the owner add three illegal floors to the eight-story structure. The building owner was arrested earlier.

A government investigator said that substandard building materials, combined with the vibration of the heavy machines used by the five garment factories inside the Rana Plaza building, led to the horrific collapse.

The government appears to be attempting to fend off accusations that it is in part to blame for the tragedy because of weak oversight of the building's construction.

During a visit to the Indian capital, New Delhi, Mr Muhith said the disaster would not harm Bangladesh's garment industry, which is by far the country's biggest source of export income.

"The present difficulties ... well, I don't think it is really serious - it's an accident," he said. "And the steps that we have taken in order to make sure that it doesn't happen, they are quite elaborate and I believe that it will be appreciated by all."

The government made similar promises after a garment factory fire five months ago that killed 112, saying it would inspect factories for safety and cancel the licences of those that failed. However, that plan has yet to be implemented.

Asked if he was worried that foreign retailers might pull orders from his country, Mr Muhith said he wasn't: "These are individual cases of ... accidents. It happens everywhere."

He has been criticised for insensitive comments in the past - even by his own party. Last year when thousands of small investors lost their savings and poured into the streets seeking government intervention, Mr Muhith said it wasn't responsible and the investors were at fault. The official death toll from the collapse has reached 512 and was expected to climb, making it likely the deadliest garment-factory accident in world history.